Police in Greater Manchester say they are under “real strain” in the wake of the terror attack last month.
Liam Curry and Chloe Rutherford, from South Shields, were among those killed in the suicide bombing at the Manchester Arena.
In the week are to be laid to rest, Manchester Chief Constable Ian Hopkins said the investigation was struggling after the loss of nearly one in four officers in recent years.
He said Greater Manchester Police is currently carrying out one of its biggest-ever investigations with 6,297 officers – down from the 8,148 officers in had in March 2010.
Writing on Twitter, he praised his officers for their “outstanding” work policing the Parklife festival over the weekend along with a protest against Islamist terrorism.
He wrote: “Outstanding from @gmpolice officers & staff this w/e policing protest & Parklife. Real strain on everyone not just this weekend ...see below.”
Under his tweet, he posted a page from the HM Inspectorate of Constabulary (HMIC) 2016 efficiency report for GMP, with a table setting out staffing statistics.
A joint funeral for Liam, 19, and Chloe, 17, will be held for the couple at St Hilda’s Church, in South Shields Market Place, on Thursday, at 10.30am, followed by a private cremation.
The couple’s families have asked that those attending wear an item of pink and blue to the service.
Family flowers only are requested, with donations in lieu of Cancer Connections.
In Manchester, more than 1,000 officers have been involved in the investigation into the May 22 attack, with hundreds of witnesses interviewed and thousands of hours of CCTV being examined.
GMP said there are now more than 8,000 entries on its logging system and 700 media devices such as mobile phones have been seized.
A total of 29 houses have been searched and 22 people arrested during the inquiry, with all now released without charge.